Word Web Version Text disappears after closing

I wrote text in a document, and it appeared to save successfully (indicated by the "Saved" icon). However, after closing the tab and reopening the document, the text had disappeared. In its place are blank spaces that preserve the exact formatting of the original text—for example, if the original text had a paragraph structure, the blank spaces repeat the same pattern.

The text is no longer accessible. I've attempted to:

• Copy the disappeared text to another document or notepad
• Select it
• Change the text color

However, no text appears in any of these actions—only the blank spaces are visible and selectable.